JP5339516B2 - Extractant made of phosphorus-containing polymer - Google Patents

Description

  The present invention relates to a noble metal or acid extractant in an aqueous solution, which comprises a phosphorus-containing polymer, that is, a polyvinylphosphine oxide compound.

Precious metals used as materials for electronic devices and catalysts, such as gold, silver, palladium, platinum, rhodium, and iridium, are limited resources, and recovery and reuse by recycling is an important issue. It has become.
As one of the efficient recovery methods, a method using a low-molecular phosphorus-containing compound such as dioctyl sulfide or tributyl phosphate as an extractant is known (see Non-Patent Document 1). (Metal ion capture method using hydroxyalkyl) or di (hydroxyalkyl) alkylphosphine oxide (see Patent Document 1), method for separating rare earth elements using trisalkylphosphine oxide such as tris (n-octyl) phosphine oxide ( Patent Document 2), a method of selectively extracting platinum using bisphenyldibutylaminomethylphosphine oxide (see Patent Document 3), and a rare metal is recovered using a chelate resin having a phosphorus atom-containing functional group A method (see Patent Document 4) has been proposed.

  On the other hand, from the viewpoint of environmental pollution prevention and reuse of useful substances, recovery of inorganic or organic acids contained in industrial wastewater is also an important issue. A method for recovering carboxylic acid in dilute aqueous solution using alkylphosphine oxide (see Patent Document 5), acetic acid and formic acid from aqueous solution of vegetable degradation products using water-insoluble organic solvent containing water-insoluble trialkylphosphine oxide. A method of extracting (see Patent Document 6) has been proposed.

  However, the low molecular weight organic compounds used as extractants in these methods are volatile and are discharged to the surroundings during the secondary treatment, causing environmental pollution and being ingested by the human body. Has the disadvantage of failing.

  The present inventors recently developed a metal extraction method using polydiphenylphosphine oxide in order to avoid troubles when using low molecular organic compounds (see Patent Document 7). It was not known whether it was effective or not.

Japanese Examined Patent Publication No. 45-21372 (Claims and others) JP-A 64-14113 (Claims and others) JP-A-11-290604 (Claims and others) Japanese Patent Publication No. 7-78264 (Claims and others) US Pat. No. 3,816,524 (Claims and others) Korean Patent No. 365,080 (claims and others) JP 2007-91824 A (Claims and others)

Shibata, Okuda, “Resources and Materials”, Society of Resources and Materials, 2002, Vol. 118, No. 1, p. 1-8

  An object of the present invention is to provide a noble metal extractant and an acid extractant that do not impair human health or adversely affect the environment when used.

  As a result of various researches on the collection and reuse of precious metals contained in trace amounts of precious metals and acetic acid, nitric acid, sulfuric acid, etc. contained in wastewater, Using this phosphine oxide as an extractant, it was found that noble metals and acids can be efficiently recovered, and that this extractant has no secondary adverse effects on the human body and living environment. It came to make this invention.

（式中のＲ¹及びＲ²は、それぞれ炭素数２〜１２の脂肪族炭化水素基である）
で表わされる循環単位で構成された質量平均分子量１，０００以上の含リン重合体からなる貴金属又は酸抽出剤、及び一般式

（式中のＰｈはフェニル基である）
で表わされる循環単位で構成された質量平均分子量１０，０００以上の含リン重合体からなる酸抽出剤を提供するものである。 That is, the present invention has the general formula

(In the formula, R ¹ and R ² are each an aliphatic hydrocarbon group having 2 to 12 carbon atoms)
A noble metal or acid extractant composed of a phosphorus-containing polymer having a mass average molecular weight of 1,000 or more, which is composed of cyclic units represented by the formula:

(Ph in the formula is a phenyl group)
An acid extractant comprising a phosphorus-containing polymer having a mass average molecular weight of 10,000 or more and comprising cyclic units represented by the formula:

  The noble metal or acid extractant of the present invention can efficiently extract a trace amount of noble metal in an aqueous solution and an inorganic acid or organic acid in wastewater, and the secondary treatment after use has no effect on human health or the environment. There is an effect that there is no adverse effect.

（式中のＲ¹及びＲ²は前記と同じ意味をもつ）
で表わされるビニルジアルキルホスフィンオキシドを有機過酸化物触媒の存在下で重合させることにより、製造することができる。 In the present invention, the dialkylphosphine oxide polymer of the above general formula (I) used as a noble metal or acid extractant is known, for example, the general formula

(Wherein R ¹ and R ² have the same meaning as above)
Can be produced by polymerizing in the presence of an organic peroxide catalyst.

  In order to use as an extractant of the present invention, it is necessary to use a material having a mass average molecular weight of 1,000 or more in order not to volatilize during the extractant treatment step.

If R ¹ and R ² in the general formula (III) are aliphatic hydrocarbon groups having 2 to 12 carbon atoms, the object of the present invention can be sufficiently achieved, but the total number of carbon atoms in the molecule is Those having 10 to 36, particularly those in which R ¹ and R ² are octyl groups are preferred.

  Next, the diphenylphosphine oxide polymer of the general formula (II) used as an acid extractant in the present invention is also known. For example, vinyldiphenylphosphine oxide is polymerized in the presence of a catalytic amount of a Grignard compound or an organolithium compound. Can be manufactured.

  As the acid extractant of the present invention, it is necessary to use a high molecular weight material having a mass average molecular weight of 10,000 or more. Although there is no restriction | limiting in particular about this upper limit of this mass mean molecular weight, Usually, the thing of the range of 10,000-1,000,000 is preferable.

  In order to extract a noble metal or an acid using the extractant of the present invention, the extractant is dissolved in a water-insoluble organic solvent to form a 0.01 to 1.0 mol% concentration solution, which contains the noble metal or acid. In addition to the aqueous solution, after vigorously mixing, it is allowed to stand still, and the organic layer is removed by separation, and the noble metal or acid contained in the aqueous phase is recovered, or the extractant is added directly to the aqueous solution containing the noble metal or acid. After adding at -1.0 mol% concentration and mixing vigorously, the extractant is filtered off and the noble metal or acid is recovered from the remaining aqueous phase.

As the water-insoluble organic solvent for dissolving the above extractant, paraffin oil, petroleum ether, toluene, hexane, chloroform, ethyl acetate, diethyl ether and the like are used.
From the viewpoint of preventing environmental pollution, a method in which only an extractant is directly added to an aqueous solution containing a noble metal or an acid without using such an organic solvent is preferable.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by this.
In addition, the measured value of the physical property used in each Example is the numerical value measured with the following method.

(1) Mass average molecular weight (a) For the vinyl dioctyl phosphine oxide polymer, the trade name “GMHHR-H * 2” (manufactured by Tosoh) is used as the column, and N-methyl-2-pyrrolidone is used as the solvent. It was measured by gel permeation chromatography using polystyrene as a standard.
(B) For the vinyldimethylphosphine oxide polymer, gel permeation using the trade name “GMHHR-H * 2” (manufactured by Tosoh) as a column and hexafluoroisopropanol as a solvent and polymethyl methacrylate as a standard. Measured by chromatography.

(2) Metal ion concentration;
It measured using ICP emission-spectral-analysis apparatus (HORIBA ULTIMA2).

(3) acid concentration;
A 0.1 mol / l aqueous sodium hydroxide solution was used, and measurement was performed with a titrator (Kyoto Electronic AT-420).

As an extractant, 0.03 mmol of vinyldioctylphosphine oxide polymer [mass average molecular weight (Mw) 1300, molecular weight distribution (Mw / Mn) 1.1] was dissolved in 3 ml of chloroform to prepare an extractant solution.
In the following manner, a commercial product having each ion concentration of 1000 ppm was diluted with pure water to a concentration of 10 ppm to prepare a noble metal standard aqueous solution.
Pd standard solution: PdCl ₂ solution in 1.0 M HCl and Pd (NO ₃ ) ₂ solution in 0.5 M HNO ₃ .
Pt standard solution; H ₂ PtCl ₆ solution in 1.0 M HCl.
Au standard solution; HAuCl ₄ solution in 1.0 M HCl.
Ag standard solution; AgNO ₃ solution in 0.1M HNO ₃ .
Rh standard solution; Rh (NO ₃ ) ₃ solution in 2M HNO ₃ .
Ir standard solution; IrCl ₃ solution in 5% HCl.

After adding 0.03 mmol of poly (vinyl dioctyl phosphine oxide) in 3 ml of chloroform, 5 ml of each standard aqueous solution containing 10 ppm of the noble metal prepared as described above was added and shaken at room temperature for 20 minutes. The organic phase and the aqueous phase were separated. About the obtained aqueous phase, the concentration of the residual metal contained therein was measured, the amount of the extracted metal was determined based on the numerical value, and the results are shown in Table 1.
For comparison, the result of using a monomer before polymerization, that is, vinyl dioctyl phosphine oxide is also shown as Comparative Example 1.

An extractant solution was prepared by dissolving 0.4 mmol of poly (vinyldioctylphosphine oxide) in 4 ml of chloroform. To this solution was added 4 ml of a 0.1N aqueous solution of acetic acid, nitric acid or sulfuric acid, shaken at room temperature for 20 minutes, and allowed to stand to separate the organic phase from the aqueous phase.
Subsequently, the acid extraction rate was calculated | required by titrating the density | concentration of the acid which remain | survives in the water phase after extraction with 0.1N-sodium hydroxide aqueous solution. The results are shown in Table 2.

  By adding 0.5 mmol of poly (vinyldiphenylphosphine oxide) to a 0.1N aqueous solution of acetic acid, nitric acid or sulfuric acid, and repeating the same experiment as in Example 2, the acid extraction rate was determined. The results are shown in Table 2.

1 mmol of poly (vinyldioctylphosphine oxide) was directly added to the aqueous solution containing 10 ppm of each noble metal used in Example 1, shaken at room temperature for 20 minutes, and then filtered to remove the polymer. The concentration of the metal remaining in the aqueous solution was measured by ICP emission spectroscopic analysis, and the extraction rate of the extracted metal was determined from the measured value.
The results are shown in Table 3. For comparison, the results of Comparative Example 1 are also shown.

  The present invention is useful for recovering and reusing noble metals and acids from industrial waste.

Claims (2)

General formula

(Wherein R ¹ and R ² are each an aliphatic hydrocarbon group having 2 to 12 carbon atoms)
A noble metal or acid extractant comprising a phosphorus-containing polymer having a mass average molecular weight of 1,000 or more and comprising cyclic units represented by:   The extractant according to claim 1, wherein the acid is an inorganic acid or an organic acid.